Sony's PlayStation Vita is an impressive piece of gaming kit, but there's room for expansion in the must-have section of its software library. Assassin's Creed 3: Liberation had the potential to help rectify this, yet somewhere between its gimmicky controls and watered-down narrative, it falls short of living up to the legacy of Ubisoft's great stealth series.

The prospect of original Vita entries in the blockbuster gaming series of this world is mouth-watering indeed, but what we have in Assassin's Creed 3: Liberation is a title masquerading as a fully-fledged console experience. All of the Assassin's Creed hallmarks are in place - from the aerodynamic free-running to the tense stealth segments - though the depth fans have become accustomed to has been offered up for sacrifice.

Assassin's Creed 3: Liberation takes place in 18th Century New Orleans and introduces the series' first female protagonist, an African-French assassin named Aveline de Grandpre. Her journey from innocent child to cold-blooded killer has all the makings of a thrilling tale peppered with commentary on the slave trade, but it feels rushed and the inter-character relationships are never fully explored.

Fortunately it delivers in the gameplay department, for the most part at least. The free-running, structure-clambering exploration translates extremely well to the Vita, and is intuitive enough to pick up and play. The game's version of American Revolution-era New Orleans is a vast, open-world playground for Aveline to explore, replete with climbable buildings, vantage points and hiding places.

Series veterans will feel right at home navigating their way across the rooftops using the Vita's twin analog stocks. The stealth segments have also survived transit to the portable platform intact. Players are encouraged to stick to the shadows at every turn, performing surreptitious takedowns and blending in with the locals. These tried and tested mechanics hold up perfectly well, and the game has a few aces up its sleeve too.

The Personas system is a core part of the experience, enabling Aveline to switch between different costumes with individual attributes. Donning her assassin's get-up helps boost combat and offers quick access to weaponry, while the Slave Persona allows her to blend in with other workers, and the Lady Persona can be used to charm guards and bend them to your will. Each personality is tied to a notoriety gauge, which causes guard patrols to pursue you more proactively when full.

Personas add a welcome injection of strategy and variety to Assassin's Creed 3: Liberation, and give players extra tools to help them meet the demands of each mission. They each come with their own side-quests too, so there's plenty to do and see under each guise.

It's not all gold, unfortunately. Melee combat is disappointingly shallow, usually boiling down to button-bashing. We found ourselves wondering whether the developers intentionally made it monotonous to encourage the stealth approach, but there are moments where it's unavoidable. Then there are those awkward Vita-specific controls.

Pickpocket non-playable characters using the read touch-pad and navigating menus via the touch-screen are all intuitive enough; the rest feels shoehorned in for the sake of making use of all of the Vita's hardware functions.

Using the touch-screens to open up letters feels unnatural, and decoding them by holding a light to the system's camera doesn't work particularly well. There also a vexing ball-rolling mini-game that uses the device's accelerometer. The majority of these features serve only to prove that although it's entirely possible for developers to include all of the Vita's features in their games, they should think twice before doing so.

Assassin's Creed 3: Liberation features an asynchronous multiplayer component that mostly falls flat. Players choose between the Brotherhood and the Templars and attempt to capture nodes on a world map. There's no hands-on combat in this mode of play, it's simply a matter of ordering your troops to attack or defend in a bid to seize control of the most territory. It's a tacked-on addition to the fold that adds little to the overall experience, and is unlikely to increase the title's replay value.

Breathtaking visuals would have been one of the game's major selling points if it didn't suffer from framerate issues. There are some gorgeous vistas to feast your eyes upon, picturesque cityscapes and thriving streets to immerse yourself in. When things are static, it's a work of art, but rough edges and animation stutters begin to creep in once Aveline is in motion.

Assassin's Creed 3: Liberation was a game with a tremendous amount of potential, but it never fully realizes it. At times it borders on brilliant, capturing the essence of the console classics and looking good doing it, yet at others it's a disappointing mix of novelty controls, frame-rate issues and weak storytelling.